PolicyEngine · MaxGhenis · Mar 2, 2026
diff --git a/changelog.d/529-batch-2.added.md b/changelog.d/529-batch-2.added.md
@@ -0,0 +1 @@
+Add 529 plan contribution deductions for MD, MA, MI, MS, MO, NE, NJ, and ND.
diff --git a/...yengine_us/parameters/gov/states/ma/tax/income/deductions/plan_529_contributions/cap.yaml b/...yengine_us/parameters/gov/states/ma/tax/income/deductions/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: Massachusetts caps the deduction for 529 education savings plan contributions at this amount.
+metadata:
+  label: Massachusetts 529 plan contribution deduction cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: Massachusetts General Laws Chapter 62 § 3(B)(a)(14)
+    href: https://malegislature.gov/Laws/GeneralLaws/PartI/TitleIX/Chapter62/Section3
+  - title: Massachusetts DOR 529 Deduction Information
+    href: https://www.mass.gov/info-details/529-plan-deduction
+
+JOINT:
+  2021-01-01: 2_000
+SURVIVING_SPOUSE:
+  2021-01-01: 2_000
+SINGLE:
+  2021-01-01: 1_000
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 1_000
+SEPARATE:
+  2021-01-01: 1_000
diff --git a/...e_us/parameters/gov/states/md/tax/income/agi/subtractions/plan_529_contributions/cap.yaml b/...e_us/parameters/gov/states/md/tax/income/agi/subtractions/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: Maryland caps the subtraction for 529 education savings plan contributions at this amount per beneficiary.
+metadata:
+  label: Maryland 529 plan contribution subtraction cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: Maryland Tax-General Article § 10-208(p)
+    href: https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gtg&section=10-208&enession=2024RS
+  - title: Maryland 2025 Resident Tax Forms and Instructions - Subtractions
+    href: https://www.marylandcomptroller.gov/content/dam/mdcomp/tax/instructions/2025/resident-booklet.pdf#page=15
+
+JOINT:
+  2021-01-01: 5_000
+SURVIVING_SPOUSE:
+  2021-01-01: 5_000
+SINGLE:
+  2021-01-01: 2_500
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 2_500
+SEPARATE:
+  2021-01-01: 2_500
diff --git a/policyengine_us/parameters/gov/states/md/tax/income/agi/subtractions/sources.yaml b/policyengine_us/parameters/gov/states/md/tax/income/agi/subtractions/sources.yaml
@@ -5,12 +5,14 @@ values:
     - md_pension_subtraction
     - md_socsec_subtraction
     - md_two_income_subtraction
+    - md_529_deduction
   2022-01-01:
     - md_dependent_care_subtraction
     - md_pension_subtraction
     - md_socsec_subtraction
     - md_two_income_subtraction
     - md_hundred_year_subtraction
+    - md_529_deduction
 
 metadata:
   reference:

diff --git a/...yengine_us/parameters/gov/states/mi/tax/income/deductions/plan_529_contributions/cap.yaml b/...yengine_us/parameters/gov/states/mi/tax/income/deductions/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: Michigan caps the subtraction for 529 education savings plan contributions at this amount.
+metadata:
+  label: Michigan 529 plan contribution subtraction cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: Michigan Compiled Laws § 206.30(1)(bb)
+    href: http://legislature.mi.gov/doc.aspx?mcl-206-30
+  - title: Michigan 2024 Individual Income Tax Instructions
+    href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040-Instructions.pdf#page=13
+
+JOINT:
+  2021-01-01: 10_000
+SURVIVING_SPOUSE:
+  2021-01-01: 10_000
+SINGLE:
+  2021-01-01: 5_000
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 5_000
+SEPARATE:
+  2021-01-01: 5_000
diff --git a/policyengine_us/parameters/gov/states/mi/tax/income/subtractions.yaml b/policyengine_us/parameters/gov/states/mi/tax/income/subtractions.yaml
@@ -9,6 +9,7 @@ values:
     - mi_standard_deduction  # Line 24 & 25
     - mi_pension_benefit  # Line 26
     - mi_interest_dividends_capital_gains_deduction # Line 27
+    - mi_529_deduction
 metadata:
   unit: list  
   label: Michigan taxable income subtraction sources  

diff --git a/policyengine_us/parameters/gov/states/mo/tax/income/subtractions/agi_subtractions.yaml b/policyengine_us/parameters/gov/states/mo/tax/income/subtractions/agi_subtractions.yaml
@@ -2,9 +2,11 @@ description: Missouri subtracts these sources from federal adjusted gross income
 values:
   2008-01-01:
     - mo_qualified_health_insurance_premiums
+    - mo_529_deduction
   2025-01-01:
     - mo_qualified_health_insurance_premiums
     - mo_capital_gains_subtraction_person
+    - mo_529_deduction
 
 
 metadata:

diff --git a/...ngine_us/parameters/gov/states/mo/tax/income/subtractions/plan_529_contributions/cap.yaml b/...ngine_us/parameters/gov/states/mo/tax/income/subtractions/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: Missouri caps the subtraction for 529 education savings plan contributions at this amount.
+metadata:
+  label: Missouri 529 plan contribution subtraction cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: Revisor of Missouri § 143.121.2(4)
+    href: https://www.revisor.mo.gov/main/OneSection.aspx?section=143.121
+  - title: 2025 MO-1040 Book - Individual Income Tax Long Form
+    href: https://dor.mo.gov/forms/MO-1040%20Instructions_2025.pdf#page=12
+
+JOINT:
+  2021-01-01: 16_000
+SURVIVING_SPOUSE:
+  2021-01-01: 16_000
+SINGLE:
+  2021-01-01: 8_000
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 8_000
+SEPARATE:
+  2021-01-01: 8_000
diff --git a/policyengine_us/parameters/gov/states/ms/tax/income/adjustments/adjustments.yaml b/policyengine_us/parameters/gov/states/ms/tax/income/adjustments/adjustments.yaml
@@ -6,6 +6,7 @@ values:
     - ms_national_guard_or_reserve_pay_adjustment # Line 55
     - alimony_expense # Line 53
     - ms_retirement_income_exemption
+    - ms_529_deduction
 metadata:
   label: Mississippi adjusted gross income adjustments
   period: year

diff --git a/...engine_us/parameters/gov/states/ms/tax/income/adjustments/plan_529_contributions/cap.yaml b/...engine_us/parameters/gov/states/ms/tax/income/adjustments/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: Mississippi caps the adjustment for 529 education savings plan contributions at this amount.
+metadata:
+  label: Mississippi 529 plan contribution adjustment cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: Mississippi Code § 27-7-18(2)
+    href: https://law.justia.com/codes/mississippi/2022/title-27/chapter-7/article-1/section-27-7-18/
+  - title: Mississippi Income Tax Instructions 2025
+    href: https://www.dor.ms.gov/sites/default/files/tax-forms/individual/80100251%202.pdf#page=12
+
+JOINT:
+  2021-01-01: 20_000
+SURVIVING_SPOUSE:
+  2021-01-01: 20_000
+SINGLE:
+  2021-01-01: 10_000
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 10_000
+SEPARATE:
+  2021-01-01: 10_000
diff --git a/...ters/gov/states/nd/tax/income/taxable_income/subtractions/plan_529_contributions/cap.yaml b/...ters/gov/states/nd/tax/income/taxable_income/subtractions/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: North Dakota caps the subtraction for 529 education savings plan contributions at this amount.
+metadata:
+  label: North Dakota 529 plan contribution subtraction cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: North Dakota Century Code § 57-38-30.3(2)(p)
+    href: https://law.justia.com/codes/north-dakota/2022/title-57/chapter-57-38/section-57-38-30-3/
+  - title: 2025 North Dakota income tax instructions
+    href: https://www.tax.nd.gov/sites/www/files/documents/forms/individual/2025-iit/2025-individual-income-tax-booklet.pdf#page=14
+
+JOINT:
+  2021-01-01: 10_000
+SURVIVING_SPOUSE:
+  2021-01-01: 10_000
+SINGLE:
+  2021-01-01: 5_000
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 5_000
+SEPARATE:
+  2021-01-01: 5_000
diff --git a/policyengine_us/parameters/gov/states/nd/tax/income/taxable_income/subtractions/sources.yaml b/policyengine_us/parameters/gov/states/nd/tax/income/taxable_income/subtractions/sources.yaml
@@ -6,6 +6,7 @@ values:
     - nd_qdiv_subtraction  # qualified dividends
     - taxable_social_security
     - military_retirement_pay
+    - nd_529_deduction
 
   2023-01-01:
     - us_govt_interest
@@ -14,6 +15,7 @@ values:
     - taxable_social_security
     - military_retirement_pay
     - military_service_income # military pay exculsion
+    - nd_529_deduction
 
 metadata:
   unit: list  

diff --git a/...e_us/parameters/gov/states/ne/tax/income/agi/subtractions/plan_529_contributions/cap.yaml b/...e_us/parameters/gov/states/ne/tax/income/agi/subtractions/plan_529_contributions/cap.yaml
@@ -0,0 +1,23 @@
+description: Nebraska caps the subtraction for 529 education savings plan contributions at this amount.
+metadata:
+  label: Nebraska 529 plan contribution subtraction cap
+  period: year
+  unit: currency-USD
+  breakdown:
+  - filing_status
+  reference:
+  - title: Nebraska Revised Statute § 77-2716(20)
+    href: https://www.nebraskalegislature.gov/laws/statutes.php?statute=77-2716
+  - title: 2025 Nebraska Individual Income Tax Booklet
+    href: https://revenue.nebraska.gov/sites/default/files/doc/tax-forms/2025/f_Individual_Income_Tax_Booklet.pdf#page=26
+
+JOINT:
+  2021-01-01: 10_000
+SURVIVING_SPOUSE:
+  2021-01-01: 10_000
+SINGLE:
+  2021-01-01: 10_000
+HEAD_OF_HOUSEHOLD:
+  2021-01-01: 10_000
+SEPARATE:
+  2021-01-01: 5_000
diff --git a/policyengine_us/parameters/gov/states/ne/tax/income/agi/subtractions/subtractions.yaml b/policyengine_us/parameters/gov/states/ne/tax/income/agi/subtractions/subtractions.yaml
@@ -3,10 +3,12 @@ values:
   2021-01-01:
     - ne_social_security_subtraction
     - ne_military_retirement_subtraction
+    - ne_529_deduction
   2024-01-01:
     - ne_social_security_subtraction
     - taxable_public_pension_income
     - ne_military_retirement_subtraction
+    - ne_529_deduction
 
 
 metadata:

diff --git a/...yengine_us/parameters/gov/states/nj/tax/income/deductions/plan_529_contributions/cap.yaml b/...yengine_us/parameters/gov/states/nj/tax/income/deductions/plan_529_contributions/cap.yaml
@@ -0,0 +1,12 @@
+description: New Jersey caps the deduction for 529 education savings plan contributions at this amount.
+metadata:
+  label: New Jersey 529 plan contribution deduction cap
+  period: year
+  unit: currency-USD
+  reference:
+  - title: New Jersey P.L. 2021, c.419 § 1
+    href: https://www.njleg.state.nj.us/bill-search/2020/A5535
+  - title: NJ-1040 Instructions 2024
+    href: https://www.nj.gov/treasury/taxation/pdf/current/1040i.pdf
+values:
+  2022-01-01: 10_000
diff --git a/...s/parameters/gov/states/nj/tax/income/deductions/plan_529_contributions/income_limit.yaml b/...s/parameters/gov/states/nj/tax/income/deductions/plan_529_contributions/income_limit.yaml
@@ -0,0 +1,12 @@
+description: New Jersey limits the 529 plan contribution deduction to taxpayers with adjusted gross income at or below this amount.
+metadata:
+  label: New Jersey 529 plan contribution deduction AGI limit
+  period: year
+  unit: currency-USD
+  reference:
+  - title: New Jersey P.L. 2021, c.419 § 1
+    href: https://www.njleg.state.nj.us/bill-search/2020/A5535
+  - title: NJ-1040 Instructions 2024
+    href: https://www.nj.gov/treasury/taxation/pdf/current/1040i.pdf
+values:
+  2022-01-01: 200_000
diff --git a/policyengine_us/parameters/gov/states/nj/tax/income/subtractions.yaml b/policyengine_us/parameters/gov/states/nj/tax/income/subtractions.yaml
@@ -9,3 +9,5 @@ values:
   # Social Security is already excluded from NJ gross income (not in gross_income_sources.yaml)
   # per NJ Statute 54A:6-15. No subtractions are needed.
   2021-01-01: []
+  2022-01-01:
+    - nj_529_deduction
diff --git a/...baseline/gov/states/ma/tax/income/deductions/plan_529_contributions/ma_529_deduction.yaml b/...baseline/gov/states/ma/tax/income/deductions/plan_529_contributions/ma_529_deduction.yaml
@@ -0,0 +1,41 @@
+- name: Case 1, single filer with contribution below cap.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MA
+    filing_status: SINGLE
+    investment_in_529_plan: 800
+  output:
+    ma_529_deduction: 800
+
+- name: Case 2, single filer with contribution above cap.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MA
+    filing_status: SINGLE
+    investment_in_529_plan: 3_000
+  output:
+    # Capped at $1,000
+    ma_529_deduction: 1_000
+
+- name: Case 3, joint filer with contribution above cap.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MA
+    filing_status: JOINT
+    investment_in_529_plan: 5_000
+  output:
+    # Capped at $2,000
+    ma_529_deduction: 2_000
+
+- name: Case 4, joint filer with no contributions.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MA
+    filing_status: JOINT
+    investment_in_529_plan: 0
+  output:
+    ma_529_deduction: 0
diff --git a/...ne/gov/states/md/tax/income/agi/subtractions/plan_529_contributions/md_529_deduction.yaml b/...ne/gov/states/md/tax/income/agi/subtractions/plan_529_contributions/md_529_deduction.yaml
@@ -0,0 +1,45 @@
+- name: Case 1, single filer with contribution below cap.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MD
+    filing_status: SINGLE
+    investment_in_529_plan: 2_000
+    count_529_contribution_beneficiaries: 1
+  output:
+    md_529_deduction: 2_000
+
+- name: Case 2, single filer with contribution above cap.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MD
+    filing_status: SINGLE
+    investment_in_529_plan: 5_000
+    count_529_contribution_beneficiaries: 1
+  output:
+    # Capped at $2,500 per beneficiary * 1 beneficiary = $2,500
+    md_529_deduction: 2_500
+
+- name: Case 3, joint filer with two beneficiaries.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MD
+    filing_status: JOINT
+    investment_in_529_plan: 15_000
+    count_529_contribution_beneficiaries: 2
+  output:
+    # Capped at $5,000 per beneficiary * 2 beneficiaries = $10,000
+    md_529_deduction: 10_000
+
+- name: Case 4, joint filer with no contributions.
+  period: 2024
+  absolute_error_margin: 0.1
+  input:
+    state_code: MD
+    filing_status: JOINT
+    investment_in_529_plan: 0
+    count_529_contribution_beneficiaries: 1
+  output:
+    md_529_deduction: 0
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Add 529 plan contribution deductions for MD, MA, MI, MS, MO, NE, NJ, and ND.